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| author | Shmulik Ladkani <shmulik.ladkani@gmail.com> | 2016-06-29 21:47:03 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-06-30 16:02:48 +0300 |
| commit | fedbb6b4ff341c1e2120f4ffbf367fd78ac3e8f3 (patch) | |
| tree | aec9b6ddce0a103d82704f52a693f1d3cd238dbb /net/ipv4/ip_output.c | |
| parent | 5ab0d6a016b19d8cbd503eafd0ef701cfd854402 (diff) | |
| download | linux-fedbb6b4ff341c1e2120f4ffbf367fd78ac3e8f3.tar.xz | |
ipv4: Fix ip_skb_dst_mtu to use the sk passed by ip_finish_output
ip_skb_dst_mtu uses skb->sk, assuming it is an AF_INET socket (e.g. it
calls ip_sk_use_pmtu which casts sk as an inet_sk).
However, in the case of UDP tunneling, the skb->sk is not necessarily an
inet socket (could be AF_PACKET socket, or AF_UNSPEC if arriving from
tun/tap).
OTOH, the sk passed as an argument throughout IP stack's output path is
the one which is of PMTU interest:
- In case of local sockets, sk is same as skb->sk;
- In case of a udp tunnel, sk is the tunneling socket.
Fix, by passing ip_finish_output's sk to ip_skb_dst_mtu.
This augments 7026b1ddb6 'netfilter: Pass socket pointer down through okfn().'
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_output.c')
| -rw-r--r-- | net/ipv4/ip_output.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 124bf0a66328..4bd4921639c3 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -271,7 +271,7 @@ static int ip_finish_output(struct net *net, struct sock *sk, struct sk_buff *sk return dst_output(net, sk, skb); } #endif - mtu = ip_skb_dst_mtu(skb); + mtu = ip_skb_dst_mtu(sk, skb); if (skb_is_gso(skb)) return ip_finish_output_gso(net, sk, skb, mtu); @@ -541,7 +541,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, iph = ip_hdr(skb); - mtu = ip_skb_dst_mtu(skb); + mtu = ip_skb_dst_mtu(sk, skb); if (IPCB(skb)->frag_max_size && IPCB(skb)->frag_max_size < mtu) mtu = IPCB(skb)->frag_max_size; |